Jason Kokrak earned a record lead at the AT&T Byron Nelson as two-time major champion Jordan Spieth sensationally missed the cut.
Kokrak was the star performer on Friday after carding an almost flawless eight-under-par 62.
The American's performance saw him move five shots clear to 12 under atop the leaderboard – the greatest 36-hole lead at the PGA Tour tournament since David Love III's four-stroke advantage in 2000.
Billy Horschel (65) is second heading into the weekend, but world number one Dustin Johnson is lurking in Irving, Texas.
U.S. Open champion Johnson posted back-to-back 67s to be tied for third at six under following the second round.
Teeing off on the back nine, Johnson was flawless as he birdied the 18th before adding another three consecutive birdies from the fifth to the seventh at Four Seasons Resort and Club Dallas.
Johnson would have been five shots adrift had he not bogeyed his final hole.
An Byeong-hun (66), Cameron Tringale (68), Bud Cauley (67), overnight leader James Hahn (70) and Jhonattan Vegas (68) are also six under.
Former world number one Jason Day is nine shots behind Kokrak following his second-round 69.
Masters winner and defending champion Sergio Garcia posted a five-under-par 65 to be two under through 36.
However, it was a day to forget for Spieth after he farewelled the tournament.
Spieth fired a five-over 75 with a quadruple-bogey nine on the par-five 16th hole as he missed the cut for the third time in four starts.
Spieth was well inside the cut line before the implosion that forced him to re-tee twice.
|Australia wait on Khawaja scan|
|Shaw signs Manchester United extension|
|Jones lays down challenge to snubbed England star Cipriani|
|West Ham´s Pellegrini rejects Dzeko speculation|
|Emery fails to assure Ramsey of Arsenal future|
|Pakistan on course for victory after Babar 99 and farcical run out|
|Canelo ready to leave comfort zone to face Fielding|
|Eriksen ready for Tottenham return, Pochettino confirms|
|Titans coach rocked by Hurrell´s Rhinos switch|
|Rubin Kazan suspended from UEFA competition for FFP breach|
|Real Madrid could sack Lopetegui if results don´t improve, says Essien|
|On-court coaching would add to drama - Mouratoglou|
|Babbel lauds ´top class´ Ronaldo after Juventus switch|
|Carmelo Anthony: Rockets bench role challenging mentally|
|Maqsood preferred to Amir in Pakistan T20 squad|
|Make Ramsey Arsenal captain, don´t let him leave – Wilshere|
|Kaneria admits guilt in spot-fixing case|
|No coach can work miracles – Ibrahimovic defends under-fire Mourinho|
|Morgan earns England recall, Cipriani overlooked|
|Reavie leads CJ Cup, solid start from Koepka|
|Juventus kicked me out to sign Ronaldo – Higuain|
|England forward Hughes given six-week ban|
|Injured Halep withdraws from WTA Finals|
|Ronaldo exit makes all the difference for Real Madrid – Luxemburgo|
|Manchester United´s Chelsea Blues and other one-sided rivalries|
|Babbel fears for Kovac´s Bayern future|
|Bradley homers again, Red Sox take 3-1 lead over Astros|
|Ayton, Doncic shine on NBA debuts|
|Leonard focusing on future after Raptors debut|
|MLS Review: Rooney stunner seals DC win, Sounders clinch play-off spot|
|Pochettino ´proud´ of Dier for Ramos tackle|
|Wallabies name three uncapped players for All Blacks clash|
|Lakers coach Walton will monitor LeBron´s minutes, plans to use deep rotation|
|Lloris: United´s Pogba unfairly judged because of transfer fee|
|´Phenomenon´ Mbappe deserves Ballon d´Or, says Buffon|
|Dodgers on cusp of World Series after beating Brewers|
|Mata braced for ´difficult month´ at Man United|
|WATCH: Rooney scores wonderful free-kick for DC United|
|Kaino handed five-week ban for striking Roberts|
|Bears star Khalil Mack ´day-to-day´ with ankle injury|
|Anthony has ´a clearer understanding´ of his role with Rockets|
|Brewers remove Miley after one batter against Dodgers|
|Rams rule out Kupp for 49ers game|
|Giants owner Mara to talk with Beckham Jr|
|Bamberg battle back to claim Champions League win|
|MLB investigated alleged Astros sign stealing, found no wrongdoing|
|Timberwolves star Wiggins to donate $22 for every point this NBA season|
|Red Sox´s Sale won´t start game five of ALCS|
|Tsitsipas and Shapovalov advance at Stockholm Open|
|Witsel to Dortmund is signing of the season - Martinez|
|Pique confident Nadal will play in 2019 Davis Cup|
|Seeds suffer in Moscow and Luxembourg|
|Johnstone grabs hat-trick as England ease past France|
|Pogba and Mourinho disagreement over Instagram video, confirms Pereira|
|Nuggets coach Malone signs contract extension|
|Mayweather accepts Khabib´s challenge: ´We´re fighting´|
|Slovenia sack Kavcic as head coach|
|Morgan and Rashid star as England win rain-reduced ODI in Sri Lanka|
|Romagnoli aims to make Gattuso proud in Milan derby|
|Naldo signs Schalke extension|
|Bills to start quarterback Anderson against Colts with Allen out|
|O´Sullivan makes 147 at ´hellhole´|
|Barcelona know when captain Messi is angry – Abidal|
|Bertens loss hands Pliskova last WTA Finals berth|
|Liverpool star Mane undergoes hand surgery|
|F1 Raceweek: Happy hunting ground for title-chasing Hamilton - US GP in numbers|
|Canelo signs record-breaking DAZN deal|
|England hit by another Vunipola injury absence|
|Gruden: Oakland Raiders ´aren´t tanking´|
|Chiesa focused and happy at Fiorentina|